Two iwi have joined a tribe taking action to resolve how a huge forest in the central North Island should be shared.

Ngati Manawa has made a High Court application after the eight iwi covered by what will be the largest Treaty of Waitangi settlement failed to allocate 176 hectares of the Kaingaroa forest between them before 1 July.

The action is against Ngai Tuhoe, Ngati Whakaue, Ngati Rangitihi, Ngati Tuwharetoa, Ngati Raukawa and the trust that received the land, near Rotorua.

The solicitor for Ngati Manawa, Kathy Ertel, says Te Pumautanga o Te Arawa and Ngati Whare are supporting the legal bid for a court hearing to revisit a mediation process.

Ms Ertel says Ngati Manawa wants all the tribes to revisit a mediation process, in which a panel of adjudicators with no links to the tribes will determine what shares each iwi receives.

(Radio NZ)